4 papers · 1 filter
The nature of the circumstellar CO_2 emission from M giants
N. Ryde, K. Eriksson, B. Gustafsson
The 13-16 um region observed by the Infrared Space Observatory (ISO) of several ABG stars are discussed. We present and analyse spectra of seven M giants which show carbon dioxide…
The rise and fall of the NaMgAl stars
Jocelyn Tomkin, Bengt Edvardsson, David L. Lambert +1
We have made new abundance determinations for a sample of NaMgAl stars. These stars, which are a subgroup of the nearby metal-rich field F and G disk dwarfs, were first identified…
Carbon Stars and Nucleosynthesis in Galaxies
Bengt Gustafsson, Nils Ryde
The role of carbon stars in the build-up of chemical elements in galaxies is discussed on the basis of stellar evolution calculations and estimated stellar yields, abundance analys…
Boron in the Extreme Pop II Star HD 140283 and the Production of Light Elements in the Early Galaxy
B. Edvardsson, B. Gustafsson, S. G. Johansson +4
Using observations of the 2496.7 A B I line with the HST GHRS at a nominal resolution of 90,000, we have found the abundance of boron of HD 140283 to be log epsilon_B (= 12 + log (…